Involvement of mesosalpinx in endometrioma is a possible risk factor for decrease of ovarian reserve after cystectomy: a retrospective cohort study

Background: Serum anti-Mullerian hormone (AMH) concentration has been used to assess ovarian reserve in patients with endometriosis, especially when endometrioma surgery is involved. Previously, we reported that decreased serum AMH levels after cystectomy for endometriomas can recover to preoperative levels in some cases. In this present study, we assessed the sequential changes in serum AMH levels before and after cystectomy in terms of the state of the mesosalpinx prior to surgery. Methods: The retrospective cohort study recruited 53 patients from a series of prospective studies conducted from 2009 to 2015. All patients underwent laparoscopic cystectomy for endometriomas. If either mesosalpinx was involved in the endometrioma or adnexal adhesion before cystectomy, the case was defined as 'involved mesosalpinx' (n = 14). If both mesosalpinx remained anatomically correct, the case was classified as 'intact mesosalpinx' (n = 39). Blood samples were obtained from the patients 2 weeks before surgery, and at 1 month and 1 year after surgery to assess serum AMH levels. Results: The serum AMH levels (the involved group vs. the intact group) were 1.92 vs. 0.98 (P = 0.552) preoperatively, 0.59 vs. 1.99 (P = 0.049) at 1 month postoperatively, and 0.48 vs. 2.37 ng/mL (P = 0.007) at 1 year postoperatively. The involved mesosalpinx group showed a further decrease in serum AMH levels at 1 year postoperatively, while serum AMH levels in the intact mesosalpinx group tended to recover. Conclusion: These results suggest that pre-existing mesosalpinx disturbance, in combination with adhesiolysis, may be involved in the medium-and long-term decrease in ovarian reserve after endometrioma surgery. A disturbance in ovarian blood supply via the mesosalpinx may underlie this.